diff --git a/concraft-pl.cabal b/concraft-pl.cabal
--- a/concraft-pl.cabal
+++ b/concraft-pl.cabal
@@ -1,5 +1,5 @@
 name:               concraft-pl
-version:            0.4.1
+version:            0.4.2
 synopsis:           Morphological tagger for Polish
 description:
     A morphological tagger for Polish based on the concraft library.
@@ -30,7 +30,7 @@
       , aeson                   >= 0.6      && < 0.7
       , binary                  >= 0.5      && < 0.6
       , process                 >= 1.1      && < 1.2
-      , mtl                     >= 2.1      && < 2.2
+      , mtl                     >= 2.0      && < 2.2
       , transformers            >= 0.3      && < 0.4
       , network                 >= 2.3      && < 2.4
       , lazy-io                 >= 0.1      && < 0.2